4-methylpent-3-en-1-yne

5-Hydroxy-2-isopropylidene-5-methyl-3-oxo-hexanoic acid methyl ester

5-Hydroxy-2-isopropenyl-5-methyl-3-oxo-hexanoic acid methyl ester

3-(2-Hydroxy-2-methyl-propyl)-5,5-dimethyl-4,5-dihydro-1H-pyrazole-4-carboxylic acid methyl ester